JPS59131293A - Network for multi-way speaker device - Google Patents

Abstract

PURPOSE:To attain optimum sound reproduction by applying to each exclusive speaker that low sound via a Bessel filter and high sound via a delay circuit so as to make the direction of large output coincident with the center axis. CONSTITUTION:An inputted signal is branched into two, and applied to the delay circuit 4 and a low pass filter 3. The low pass filter 3 is constituted by the Bessel filter. The delay circuit 4 gives a referenced delay time to the input signal. A woofer 1 is driven by an output signal of the low pass filter 3. A part of the output signal of the low pass filter 3 is applied to a subtractor 6. The subtractor 6 subtracts an output signal of the low pass filter 3 from the output signal of the delay circuit 4. A high frequency signal is obtained at the output of the subtractor 6. A tweeter 2 is driven by this signal. The phase difference between both the speakers is zeroed and an excellent linear phase network is obtained.

Description

[Detailed Description of the Invention] Does this invention apply to the vicinity of the crossover frequency? This invention relates to an odd work for a multi-way speaker device in which a speaker device with natural sound quality is obtained by matching the direction of the axial force of the speaker with the main extremely thick force of the synthesized sound pressure generated by the bass speaker S and the treble speaker. 1°R〇The system shown in Figure 1 has been proposed as a linear phase network. The input signal is branched into two, one being applied to the bass speaker I through a low-pass filter 3, and the other being the bass speaker IK711.]
The signal input power ρ) to be selected is subtracted by a subtractor and added to the high-pitched speaker 2.

Iha, considering the sum of the transfer functions of bass speaker l and treble speaker 2, 'h, (S) + To (S) = TL (S) + [1 - TL
(S) l = 1 ・river ・(ll, and a linear phase network is realized.

Here, S is a plurality of frequencies (=σ+jcA)).

Here, transfer functions TL and TH are expressed as amplitudes ML and MH and phase 1
Looking at 1L and 1H, %TLITH is expressed as follows.

TL (j c, >) = ML(u) e jOL(
W) −=−= (21T H(Cd)
= MH(u)e jj'H(ko")
・==・(3) However, υJ is the angular frequency.

Figure 2 shows the standardization frequency X = 1/ω0 (υ is the reference angular frequency), Tt, (jx) = 1/(1+jX)
・=−(41) Amplitude M L(X), M
H(X), phase da L(X).

l　H(X) is calculated.

As is clear from FIG. 2, the difference between the phases OL and OH is 90° regardless of the frequency, and they are never in phase.

1k, transfer function Tt, (jx) can be considered in countless ways other than equation (4), but in general, one phase OL and OH are in phase because the condition of equation (1) is maintained. It can't actually happen.

Based on this, next we will consider the case where there is a phase difference (yiHI L') between the bass speaker l and the treble speaker 2.

Figure 3 shows the distance d between bass speaker l and treble speaker 2.
The model diagram shows a case in which the speakers are placed on the baffle surface 5 with a distance l separated from them. In this figure, the distance difference l from both speakers to the observation point p at a long distance is expressed as It is calculated as follows.

1'=d1sinα・・・・・・
・(5) This distance difference 1+1 ultimately affects sound radiation as a phase difference between both speakers, so the phase difference between the sound pressure from high-pitched speaker 2 and the sound pressure from low-pitched speaker l at observation point p △ψ is expressed by the following formula.

ΔFurnace=PHOL+360°d, 5in(X/λ・
(6) However, in this equation (6), λ is the wavelength.

Therefore, △ψ=±n 360c' (n=o, 1.Z...)
...In the case of (7), the sound pressure does not add up and becomes maximum, △furnace=±(2n+1)180°(n=0.1.
2.・=−)・・・・・・−(8) When the sound pressures cancel each other out and become minimum.

In particular, the main thick direction when Δψ-0 is determined by the following equation from equation (6).

As mentioned above, since (0■, -1H) is not 0, α cannot be θ° (in other words, it is either the main thick direction or the direction of the central axis in Figure 3 (speaker axial direction)). It's never the same.

FIG. 4 shows an example of calculating the sound radiation pattern for the transfer function TL(jx) expressed by equation (4). L
However, it is assumed that λ/d=1.

As can be seen from Fig. 4, the main thick direction is shifted from the center axis by about 14.5 degrees toward the bass speaker, and assuming that the listener is on the center axis, the sound emission direction is different.
Optimal sound reproduction cannot be obtained.

This invention was made in order to eliminate the drawbacks of the prior art as described in -F, and by setting the phase difference between the bass speaker and the treble speaker to 0, the main thick direction and the center axis rotation are made to coincide with each other. The purpose of the present invention is to provide a network for a multiway speaker device that can provide optimal sound reproduction to a listener.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a multi-speaker network according to the present invention will be explained below based on the drawings. FIG. 5 is a block diagram showing the configuration of one embodiment. In FIG. 5, parts that are the same as those in FIG.

In this figure 5? %The difference from Figure 1 is that the delay circuit 4
The point is that That is, the delay circuit 4 is not inserted into the input ill of the subtractor. Other parts 1st
It is similar to the figure.

With this configuration, in FIG. 5, if we consider the sum of the transfer functions of the bass speaker] and the treble speaker 2.

TL(S) + TH(S) = TL(S) + (
e”-Ty, (S) 1=e-78...(
The synthesized transfer function also exhibits a linear phase characteristic with a delay time.

Next, consider the phase difference between bass speaker l and treble speaker 2 (
The transfer function TL and delay time used in this invention, which are set to 0, will be explained.

Low-pass filter T L &! used in this invention! This is a group of Bessel filters with a transfer function of 5 as shown in the following equation.

However, what about this 01) formula? and K is a constant.

Bn(S) is a polynomial expressed by the following equation.

To the above 011 type? If we set K=1 and specifically show the transfer function for rl=1 to 5, the following (1312 to u7
) is as follows.

Tr,'(S)=1/(l+s)−・−・Q3)T?
, (S)=3/Ia+-as+as2)
...... (141Tr:'(S)=15/(
15+15s+]5s”) ・・・・・・
(15)'rr(S)=105 (105+1058+
45S2+tO83+S') ・・・・・・Q6)T
L'(S)=945/C945+945S+42O8
2+1058"15s' +S 11)
--Q7) 1, TLn(S) is generally defined as TL''(S) = 1/U+a, s+a2s+-...
・−+ana”)−−−−−−OB, uO= (&n)−”
--Q9,=sro.・
(201), the QgJ formula is standardized and transformed into the following formula.

Tt,”(p) −1/(1+b, p+b2p2+・−
10 bn-1P"-'+p")...(21) Specifically, in the form of formula (2I), ([31 formula to (171 formula) are transformed.

These are as shown in formulas (24 to (2G)).

TL'(p)='/(1+p)
...@TL'(p)=1/(1+%/Tp10p
2) -...-(23)TL
”(p)=1/(1+2.4662IP+2.4328
81) 2+Il') ...-QATL'(p)
= 17(1+a2oto9p+4.391ssp2+
a, 12a94p'+p')...(25) TL5(p)='/(1+3.936281)+6.
88637p”+6.77667ps+a, gto7o
p'+p5) ・・・・・・(26)
In the case of l-I, the delay time used in this invention is chosen to be %+21 when expressed as a standard using equation (20), as in the case of the transfer function. Namely.

te n=b,=ω,
...It's a hut. However, te n is a standardized delay time.

FIGS. 6(a) to 6(e) show the Tt determined as above, "(P)%J:HiTHp(P)ILTl=jXtL,".

Amplitude characteristic ML"(X) regarding standardization frequency X.

MH" (X) To position a'Fi! E OL" (x),
$)+”(x) Y Calculated for 121-5.

However, TL” (3M), TH” (3X) 1ML”
(X) ,M,,”(X).

The relationship between stones, "(X), 0.(" (X) is as follows.

T Ln(jx)−ML” (x) 6 jOr, n(
x))...T n(jX)=e-te"jx-TH"(jX)-
MHn(x)e""(x) 6th [iQ+ As seen from (a) to FIG.
1. ” (x> and treble speaker 20th place a l Ln
(X) are almost equal in a region where X is small.

Moreover, the larger te n becomes, yILn (X) =
The region where pHn (X) expands in the thicker direction of H"
(x).

As a friend, I put J on bass speaker L and treble speaker 2.
The sound radiation pattern of the synthesized sound pressure created by .

By the way, the contents I have clarified in this section also refer to the 2-way speaker system in Part A of the multi-way speaker device, but even for devices with 3-way speakers or more, the contents described in 11-1 do not apply at all. Similarly, it can be applied to devices with three or more units.

7. This is an example of a linear phase network according to the present invention constructed using the 7th [13 U/A method]. In this FIG. 7, the human input signal is filtered through a low-pass filter 3a)
7 and is applied to a bass speaker l, and the input signal is applied to a subtracter Da through a delay circuit 4a and a low-pass filter 3b.

In this subtracter Da, two low-pass filters 3a and 3b are used.
By subtracting between the outputs of , the midrange speaker 7 is driven.

Furthermore, the output of the delay circuit 4a passes through a delay circuit 4bi and is applied to a subtracter Db.

The output of the low-pass filter 3b is also input to this subtracter DbK, and 29. A subtracter Db subtracts the output of the low-pass filter 3b and the output of the delay circuit 4b, and the mid-range speaker 2 is driven by the output.

As will be explained hereinafter, the multi-way speaker device network of the present invention branches an input signal into at least two parts, applies a low-pass filter to the input signal, and adds the low-pass filter to the low-frequency speaker. , the other signal is sent to the rear bass speaker via a delay circuit using a linear phase network Z that subtracts the signal that should be sent to the treble speaker, and a Bessel filter is used as a low-pass filter. Since the delay time of the delay circuit is selected to match the delay of the Bessel filter, n=b, the phase difference between the bass speaker and the treble speaker is 0.
Therefore, the main thickest direction of the sound radiation pattern created by both speakers coincides with the axial direction of the speaker, and it is possible to provide optimal sound reproduction Y to the listener, and also to provide a natural sound reproduction pattern. It's all about getting the sound quality.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the basic configuration of a conventional linear phase network, Fig. 2 shows an example of calculation of amplitude characteristics and phase characteristics when using a conventional linear phase network, Fig. 3 Figure 4 is a model diagram showing the state in which bass and treble speakers are placed on the baffle surface with a distance of d, 4. Figure 4 shows the sound radiation pattern of the composite sound pressure created by the bass and treble speakers. FIG. 5 is a block diagram showing the configuration of an embodiment of the multi-way speaker device network of the present invention, and FIG.
a) to FIG. 6(e) respectively correspond to the multiway speaker device network of the present invention? Characteristic diagram showing an example of calculation of amplitude characteristics and phase characteristics when Bessel filters from the first order to the fifth order are used as low-pass filters to provide a delay time suitable for each Bessel filter to the delay circuit, No. 7 The figure is a block diagram showing the configuration of another embodiment of the multiway speaker device network of the present invention when applied to a three-way speaker device. l... Speaker for bass % 2.7... Speaker for medium tone, 3, 3 a, 3 b... Low pass filter, 4
, 4a, 4b...delay circuit, 5...buckle surface, D
, Da, Db...subtractor. X, the same symbol in the figure indicates the same or equivalent part O Agent Shin Kuzuno (1 person) 2-1 Figure 16 (4) =/ □1 (So 4 Ne (i more tusk 6 Figure (b) 22 □丞耀-Latitude Z spear 6 Figure (C) Nine □1 Keyaki I Jin/) 7 Hayashi Ei χ Fang 6 Figure Cd) Nine = 4 □Junza/C To Fuki Daikyō □昶ｶｮｮｮｮｲｲ 7 Illustration procedure amendment (spontaneous) 58 b 30 Showa year month ``1 1 effect' 1° Director's office 1 ・If S'l indication f , 7, 1liji No. 58-5661; 3. Nagisa representative piece to be corrected 111 Jin 8 part 5, subject of correction 6, contents of correction (1) ft1l Thin IIf second page 1st line 7-8 The statement "Linear phase network... has been proposed in the past" should be corrected as follows. Originally, in order to faithfully transmit a signal, a so-called linear phase characteristic, in which the phase characteristic changes linearly with frequency, is required. For this reason, a linear phase network as shown in FIG. 1 has been proposed as a speaker device network. (2) In the 17th and 18th lines of the second page, the statement "is a linear phase network..." is corrected as follows. This will be recorded. Equation (1) means faithful reproduction in which the input signal becomes the output signal as it is, and moreover, the phase change of the output signal TL (S) is 0' regardless of the compound blade frequency S (= 6 + j m). The network in Figure 1 has an angular frequency of 9
The phase characteristic becomes a straight line, that is, it becomes a linear phase network. (3) On the 2nd line of the 4th page, the words ``Model Diagram'' should be corrected to ``Model Diagram''. (4) On page m6, lines 15-16, “Synthesized...
-... Refers to linear phase characteristics. '' should be corrected as follows. The synthesized transfer function 'l'', (S) shows a constant delay characteristic. Therefore, its phase changes linearly with rIi with respect to the angular frequency ω, and the network in Fig. 5 is a linear phase network. (5) In the 7th line of the 7th page of n, 1=1 2 (n-1) !1! is corrected to 1=0 2 (n-1) I i +. (6) Same number r TL(S) = 105 (105+...+S4) on page 7, line 14
”, r T' (S)=105/ (105+
105S+453-1-1O5+S)J and correct it. (7) On the 4th line of the 9th page of the same page, amend the text "r T,, Regarding (P)" to read r T: Regarding (P). (8) The ``n'' in the 6th line of the 9th page of the same page is 21
5 Correct as “n=, 1 to 5”. (9) In the 5th line of page 10, the phrase ``maximum acoustics'' is corrected to ``optimum acoustics.''

Claims (1)

[Claims] Let n4 be the order of the low-pass filter, b,, b2゜−, b
n-1 constant, It' complex frequency, and TL''(p
) Y low-pass filter, and this transfer function TL''(p) is TL''(p)=
1/(1+b, p+b2P2+--bHIpn-10P
”), the input signal is split into at least two parts, one of which is sent to the bass speaker via a low-pass filter, and the other signal is sent to the bass speaker after passing through a delay circuit. The signal to be added to the filter is subtracted from the signal to be added to the treble speaker, and the Bessel Two Iltan is used as the low-pass filter, and a standardized delay time bI is given to the delay circuit. A network for multi-way speaker devices featuring the following features: